When someone has the target painted using SOFLAM (or possibly CITV station), does locking on with JAV or Guided Missile require less lock-on time?
According to Battlefield.wikia, referring to Guided missiles,
The missile can be countered using IR Smoke, causing it to miss its target. The Guided Missile also has the ability to lock onto laser-designated targets provided by teammates, decreasing lock-on time and increasing damage due to the top-down attack.
The javelin page does not mention it, but from my personal experience, locking onto a designated target does indeed take less time than an undesignated one.